Gutting the exhaust

Well ive been doing some research on an exhaust for the bike (05 636) and at the moment i couldn't fork out that kinda cash for an exhaust.
Did some more reading and ive seen some people gut the stock exhaust to get the tone they want. Basically they keep the baffle in as it also acts like a heat shield and protects the outer casing from excessive heat, but they remove the maze of chambers within the muffler.
Seen the inside of it and in theory it all sounds like a moderate job, although id need to get it welded up again and im not sure if welding stainless steel is any different to your normal metal.
But has anyone done this before? will i need to get the thing dyno'd after ive done it? will it lose all of its bottom end due to the lack of back pressure?
Thanks
Did some more reading and ive seen some people gut the stock exhaust to get the tone they want. Basically they keep the baffle in as it also acts like a heat shield and protects the outer casing from excessive heat, but they remove the maze of chambers within the muffler.
Seen the inside of it and in theory it all sounds like a moderate job, although id need to get it welded up again and im not sure if welding stainless steel is any different to your normal metal.
But has anyone done this before? will i need to get the thing dyno'd after ive done it? will it lose all of its bottom end due to the lack of back pressure?
Thanks